Recent data strongly indicate that smoking onset among youth, for the first time in decades, is significantly rising (CDC, 1999; Wechsler et al., 1998). Current smoking among African American adolescents has increased 80 percent, compared with a 28 percent increase among Caucasian adolescents (CDC, 1998). This rise in smoking among Black youth is particularly alarming, as this group already suffers a greater preponderance of smoking-related diseases (USDHHS, 1998). Information on the causes of smoking among young African Americans is critically needed; however, few studies have examined the determinants of smoking onset in minority youth. Thus, research is critically needed to identify the factors that prompt young adults in general, and certainly African American young adults to initiate smoking. In addition, we need to understand the natural history of these smoking behaviors in a primarily Black population. With this Introduction in mind, we propose the following Specific Aims: (1) To track participants of the Memphis Health Project (MHP), a study that has followed primarily low income, minority youth since the 7th grade (participants are now in 12th grade), prospectively for four years post-high school, in order to assess the extent of young adult onset and cessation in this biethnic population. (2) To determine the predictors of smoking onset, not only in early onset smokers (e.g., before age 18) but also in late onset (after age 18) smokers as well. It will be particularly important to determine if patterns of behavior in middle or high school (e.g., consistent experimentation with cigarettes, use of smoking paraphernalia) predict later young adult onset smoking. (3) To determine the predictors of conversion from experimental smoking to regular, adult patterns of smoking, not only in early onset smokers, but in late onset smokers as well. Existing data suggest that for African Americans, the transition to regular patterns of adult smoking occurs later than for other groups, and it is important to determine whether the factors predictive of this transition differ as well. (4) To identify the predictors of cessation for both early onset and late onset smokers. Recent data from this study suggest that cessation may be significantly less common among African Americans than Caucasian youth, and it is important to document this pattern and understand the predictors of cessation among African American youth and young adults.